1. Field of the Invention
The invention relates to a cutter assembly for mowing apparatus. The invention is more particularly concerned with a sickle guard for a cutter assembly of mowers. The cutter assembly comprises a sickle guard having at least one guard, wherein each guard comprises a guard body and an upper lip secured to the guard body, wherein between the guard body and the upper lip is provided a knife slot to receive knife sections secured to a reciprocable knife back, wherein each guard body has a ledger surface facing the knife sections and with lateral cutting edges, wherein each knife section is provided with a bottom face and lateral facets defining knife section cutting edges, wherein each guard is releasably secured at least by its guard body to a cutter bar, and wherein hold-down means are provided for holding down the knife sections in the direction towards the ledger surface of the guard bodies.
2. Description of the Prior Art
In one known sickle guard of this type (GB-A-1155464) cast or forged hold-down clips are arranged at spaced intervals along a mounting member. Each clip is T-shaped in plan view and is fixed by means of two guard mounting screws to the cutter bar. A forwardly extending portion has an undersurface arranged to come into sliding contact with the upper faces of the knife sections. The clips and their assembly and possible adjustment perpendicular to the upper faces of the knife sections are costly and heavy.
From U.S. Pat. No. 3,722,196 it is known to divide each hold-down clip into a mounting flange and a hold-down arm which is linked thereto so as to be capable of being raised and lowered. By means of an adjustment screw inserted into the rearward end of the hold-down arm and engaging at against the cutter bar, there is a minimum distance between a lower guide face of the hold-down arm and the knife sections. This design requires increased expenditure.
From the French patent application 2546367 A1 it is known to adjust the height of the knife slot so that instead of an upper lip, one has a separate upper portion of the sickle guard which is able to be raised and lowered on a mounting screw. The upper portion has a fixed support runner behind the screw and an adjustable support screw in front of the screw. The supports and rest on a carrier plate which is supported on the cutter bar by means of a spacer plate. This design is associated with particularly high manufacturing and assembly costs.